ABSTRACT
A new spider species belonging to the genus Agroeca Westring, 1861 is described. Agroeca istia sp. n. has been collected in southern Navarra, Spain. The description is based on 21 individuals of both sexes, present throughout the year on the ground of pine forests and surrounding low vegetation of the Natural Reserve Vedado de Eguaras.
Subject(s)
Pinus , Spiders , Animal Distribution , Animals , Female , Forests , Male , SpainABSTRACT
Agricultural landscape homogenization has detrimental effects on biodiversity and key ecosystem services. Increasing agricultural landscape heterogeneity by increasing seminatural cover can help to mitigate biodiversity loss. However, the amount of seminatural cover is generally low and difficult to increase in many intensively managed agricultural landscapes. We hypothesized that increasing the heterogeneity of the crop mosaic itself (hereafter "crop heterogeneity") can also have positive effects on biodiversity. In 8 contrasting regions of Europe and North America, we selected 435 landscapes along independent gradients of crop diversity and mean field size. Within each landscape, we selected 3 sampling sites in 1, 2, or 3 crop types. We sampled 7 taxa (plants, bees, butterflies, hoverflies, carabids, spiders, and birds) and calculated a synthetic index of multitrophic diversity at the landscape level. Increasing crop heterogeneity was more beneficial for multitrophic diversity than increasing seminatural cover. For instance, the effect of decreasing mean field size from 5 to 2.8 ha was as strong as the effect of increasing seminatural cover from 0.5 to 11%. Decreasing mean field size benefited multitrophic diversity even in the absence of seminatural vegetation between fields. Increasing the number of crop types sampled had a positive effect on landscape-level multitrophic diversity. However, the effect of increasing crop diversity in the landscape surrounding fields sampled depended on the amount of seminatural cover. Our study provides large-scale, multitrophic, cross-regional evidence that increasing crop heterogeneity can be an effective way to increase biodiversity in agricultural landscapes without taking land out of agricultural production.
Subject(s)
Agriculture , Biodiversity , Crops, Agricultural , Ecosystem , Animals , Bees , Birds , Butterflies , Europe , Humans , North America , SpidersABSTRACT
One new species of Triphleba Rondani and eight new species of Megaselia Rondani are described from Montseny Natural Park (mainland Spain). The new species are Megaselia arbuciensis García-Romera sp.nov., Megaselia barrientosi García-Romera sp. nov., Megaselia callunae García-Romera sp. nov., Megaselia carminis García-Romera sp. nov., Megaselia ivanis García-Romera sp. nov., Megaselia longianalis García-Romera sp. nov., Megaselia montseniensis García-Romera sp. nov., Megaselia sarae García-Romera sp. nov., Triphleba beatricis García-Romera sp. nov.
